Molecular typing of clinical Cryptococcus neoformans isolates collected in Germany from 2004 to 2010

Abstract

Cryptococcosis is a fungal infection mostly caused by Cryptococcus neoformans. We identified agents of cryptococcosis diagnosed in Germany from 2004 to 2010. We used multi-locus sequence typing (MLST) to understand the molecular epidemiology of cryptococcosis. Sero- and mating types of individual patient isolates were determined by PCR. MLST was performed using the seven-locus scheme. Allele and nucleotide diversity was calculated for each locus of C. neoformans var. grubii and C. neoformans var. neoformans. Phylogenetic relations were assessed by dendrograms. Clinical data were compared between infections caused by the two variants. We studied 101 isolates. Eight were identified as hybrids (8%). All non-hybrids were of the α mating type. Among 78 C. neoformans var. grubii (77%), 16 sequence types (STs) were identified including three novel STs. They clustered in four groups, previously isolated in Asia, Europe or worldwide. Among 15 C. neoformans var. neoformans (15%), 10 STs were identified, without clustering. These isolates showed higher allele, and nucleotide diversity compared with C. neoformans var. grubii. C. neoformans var. neoformans was more likely to cause soft-tissue infections (3/9, 33 vs. 1/63, 2%, p = 0.005) and to affect non-AIDS patients (7/14, 50 vs. 15/76, 20%, p = 0.036). C. neoformans var. grubii is the predominant agent of cryptococcosis in Germany. MLST suggests that a part of these cases are acquired abroad by immigrants or tourists. C. neoformans var. neoformans isolates represent a greater genetic diversity and are associated with more variable clinical presentations.

MLST-Based Population Genetic Analysis in a Global Context Reveals Clonality amongst Cryptococcus neoformans var. grubii VNI Isolates from HIV Patients in Southeastern Brazil

“…For example, ST5, which was one of the most prevalent STs amongst the clinical isolates from Europe and Asia [34, 90–92], was only identified in two clinical and one environmental isolate from Brazil. Other STs seem to be very uncommon, for instance, ST289 was only found in one clinical sample in this study and in few occasions in Germany [90]. Since some STs are more prevalent in different regions, and to develop an overarching view of the C .…”

Multilocus sequence typing analysis reveals that Cryptococcus neoformans var. neoformans is a recombinant population

“…In addition, data obtained from previous studies of 30 C. neoformans var. grubii isolates (11 VNB, 10 VNI, and 9 VNII) were included in the analysis as outgroup strains (Khayhan et al, 2013; Litvintseva et al, 2006; Sanchini et al, 2014; Cogliati et al, 2013; Meyer et al, 2009; Kaocharoen et al, 2013; Choi et al, 2010; Umeyama et al, 2013; Wiesner et al, 2012) (Table S1). …”

“…The data of strains WM629, CBS7816, PD32, PD2270, PD1596, RKI 08-0429, RKI 04-0089, RKI 09-0388, RKI 09-0515, RKI 07-0173, RKI 05-0151, RKI 04-0061, RKI 09-0393, RKI 09-0545, RKI 09-0102, RKI 09-0103, RKI 11-0048, RKI 08-0591, RKI 08-0572, RKI 11-0047) were obtained from previous studies (Sanchini et al, 2014; Kaocharoen et al, 2013; Meyer et al, 2009; Danesi et al, 2014). …”

“…In developed countries, however, the incidence of cryptococcosis in HIV-infected population is decreasing due to the introduction of high active antiretroviral therapy (HAART). In contrast, the disease is increasingly found in non-AIDS patients such as those with hematological neoplasms, recipients of organ transplantation, and victims of autoimmune diseases (Bratton et al, 2012; Henao-Martínez and Beckham, 2015; Sanchini et al, 2014). …”

Cryptococcosis due to Cryptococcus gattii in Germany from 2004–2013

“…In addition, identification of all C. neoformans isolates from 2004 to 2010 was confirmed by specific PCR assays as reported previously (Sanchini et al, 2013). The serotype of isolates received from infections diagnosed between 2011 and 2013 and all C. gattii isolates was identified by a PCR assay targeting the STR1 gene (Feng et al, 2013a).…”